The invention concerns a cleaning device for the printing cylinder of a rotary printing press, with a guide rail placed somewhat parallel to the printing cylinder, on which a longitudinally movable carriage slides, and upon which a washing apparatus is releasably mounted, whereby the guide rail, in order to place the washing apparatus before the printing cylinder, is controllingly displaceable, and wherein the washing apparatus is connected to a supply center by means of supply lines for washing detergents, air, electrical current, and the like.
On a rotary printing press, due to normal operation and dependent upon the kin of color and the paper to be printed, buildups of colors and paper dust form. This buildup increases with the quantity of printing, and after a certain amount has accumulated, the printing quality is negatively affected.
In most cases, the usual printing cylinder, which may be made of rubber cloth, is manually cleaned during a machine stop, which practice, besides the expense, presents safety risks for the personnel, since the cylinder rotates with a motorized drive.
For some time, automated washing systems for the cleaning of the printing cylinder have been installed. These systems are based on a rotating brush or a cleaning cloth which periodically unwinds itself and by means of a nozzle spray system is wetted with a selected detergent and water. The cleaning process is carried out by means of placement of said cloth on the rotating printing cylinder. All these systems clean by the application of a detergent.
Such washing systems are specific to each printing cylinder and are installed, to wash the printing cylinder in an appropriate cycle, between a number of printings in one run and/or after the end of the printing run. By means of this washing, the color and paper dust deposits are cleaned away. The freshly cleaned rubber cloth of the rubber cloth cylinder now assures a continuation of printing of the current run with a good degree of quality, or provides the proper starting conditions after a change of print order.
The washing systems are mostly automatically activated, and installed on the printing cylinder and are initiated by a specified washing program from the control station of the rotation equipment or by means of a master controller.
A disadvantage of these wash systems which are found on the market, is the specific attachment to only one printing cylinder. Especially during mounting of the wash system, the integration of the equipment into the printing machine becomes a complex operation. In addition to this, design accommodations are necessary, matching each rotation machine type and rotation machine format, with consideration given to the cylinder circumference. The design then extends itself not only to the wash system but also to the rotary machine itself.
Further disadvantages lie in the width of the washing system. All systems must have the same axial width as the cylinder to be cleaned. Disadvantages are further conditioned by the rigid installation and dedication to a specific printing cylinder. Further, consideration must be given to the technical construction of the cylinder as well as to the limited ergonomical possibilities.
The required accessibility for the operator is, with the above assembly, limited. Thus, the rubber cloths, which are found on the rubber cloth cylinder and which, due to damage or wear during or after the print run, have to be changed, can only be changed when the particular washing system is dismantled and removed.
A further disadvantage is that systems, because of their stationary installation on the specific printing roll, are, as a rule, not generally exchangeable. Analogously then, the number wash systems to be installed will be the same as the number of printing rollers.
Yet a further disadvantage is the amount of service, cleaning, and maintenance which calls for a high expenditure of technical time.
EP 0 928 687 A1 discloses a rubber cloth cleaning device, which is smaller than the breadth of the printing cylinder to be cleaned. This cleaning device can be moved along a guide rail parallel to the longitudinal extent of the printing cylinder. Thereby, by the pushing of the cleaning device along the guide rail, the accessibility and vision at any optional point on the rubber cloth cylinder is made possible.
In the case of this cleaning device, the connection of the in and out flow lines from an external, central supply point is directly through a central supply hose to the washing apparatus. The central supply hose is, in this case, conducted by a carrier, whereby, a sufficient freedom of movement must be allowed to compensate for the movements of the wash apparatus. These hoses, in the case of generally tight space requirements of the printing machines, are not particularly desired, because of the loose line guidance due to the movement of the washing apparatus. This arrangement is also disadvantageous, because, among other things, of the danger of damage.
From safety considerations, it is often not allowable to supply electrical energy, hot water, and detergent by means of one loose central supply hose in the direct proximity of rotating printing cylinders. The supply hose could be a central consolidating carrying in turn the supply hoses for said media. Added to these, could be another hose for the return flow of the spent water-detergent mixture.